I'm Catholic, but I've never been told one can only be married in the Church. You're not supposed to be married outside of your own church, or you can't be if you or your spouse are divorced, from another church, living with your fiancée, crap like that. Too many stupid rules (I suppose that's why I no longer go -- that and I don't like the Pope, or what's going on with all the sex abuse stuff), but there's nothing there about the government forcing the church to marry gay couples. Any Church call say yes, or no and there's nothing the government can say or do.
A gay couple can be married by a Justice of the Peace, or even a boat Captain. You don't need a church to be married, or to make it legal. That's why I don't get the argument for all this God created marriage crap. It's complete BS.
-Wolf.